As for the technical background, U.S. patent application (U.S. Pat. No. 5,848,539 (A) published on Dec. 15, 1998) is known, which describes a piece of jewelry with a set of medium-sized stones, where each stone has at least one cutout groove. The base has two interior sidewalls and two opposite exterior sidewalls formed directly by the base which extend from the base to form seats in which a sidewall has an inward-facing protruding projection. The product has at least two zigzag sidewalls that separate the seats and form three rows, and the zigzag sidewalls have the inward-facing protruding projections placed into the row, which are inserted into the carved out stone groove after the stone is mounted in a seat.
A weak point of such known technical solution after the U.S. Pat. No. 5,848,539 (A) is the complexity of its implementation, which does not affect the setting strength of the final product. Availability of the zigzag grooves does not allow the solution to be applied in a number of product designs having seats because a product base should have a flat surface only. In addition, stones can only be placed on the surface of a piece of jewelry, and the part of a jewelry with the stones must be limited with a sidewall formed by the base. The presence of carved out grooves in stones complicates the process of preparing stones for their mounting on the surface of a jewelry.
One more U.S. patent application is known (U.S. Pat. No. 5,377,506 (A), published on Jan. 3, 1995), which describes a method of mounting stones in a piece of jewelry made of a metal or a metal alloy, for stones used in a jewelry decoration and mounted on the surface of the base in seats. The set of stones of a larger and smaller diameter that are round in view from above or have a round gem-cutting, elongated down pavilion and a small radius of curvature of the girdle peripheral edge, is placed on the surface of the base of a piece of jewelry. Each precious stone pavilion is inserted into an appropriate seat. The inserted stones are held in seats at least by means of ledges or beads that are formed on the edge of the seats.
A disadvantage of such solution after the U.S. Pat. No. 5,377,506 is insufficient reliability of mounting stones of a smaller diameter.
It is caused by the fact that the protruding projections or beads are formed by drilling through holes of the same diameter for stones with a larger and smaller diameter, which are then expanded from outside by means of a larger diameter drill. On the edges of seats the protruding projections or beads are formed, and the stones of a larger diameter are fixed in the seats by means of beads, and the stones of a smaller diameter are held in their seats only due to pressing a pavilion of each larger diameter stone of the crown to at least one smaller diameter stone at least partially to the edge and/or sidewalls seats. Lack of protruding projections or beads for mounting stones of a smaller diameter in seats results in their falling out of seats if a neighboring stone of a larger diameter is fallen out.
Besides, stones with a larger diameter are separated by protruding projections or beads, which reduces the base area of a piece of jewelry, filled with stones.
After refinement, projections or beads have a pointed shape, which causes clutching of jewelry with clothes and a further displacement of projections or beads. Change in projection or bead position results in decreased reliability of mounting stones and leads to their loss. In addition, loss or damage of at least one projection or bead leads to the loss of the stone.
Based on the above background, it was found that the problem of achieving high reliability in mounting stones on a jewelry base and providing a high percentage of filling the surface of the base with the precious stones has not been solved.